#include<iostream>
#include<set>
using namespace std;
int main()
{
    set<int> myset;
    set<int>::iterator it;
    for (int i = 1; i < 10; i++)
    {
        myset.insert(i*10);
    }
    myset.insert(65);
    myset.insert(2);
    myset.insert(1);
    it=myset.find(30);
    if (it!=myset.end())
    {
        cout<<"30 is found"<<endl;
    }
    else
    {
        cout<<"30 is not found"<<endl;
    }
    myset.erase(50);
    cout<<"myset contains:";
    for (it=myset.begin(); it!=myset.end(); it++)
    {
        cout<<" "<<*it;
    }
    cout<<endl;
    return 0;
}